1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3 * Miscellaneous cgroup controller.
4 *
5 * Copyright 2020 Google LLC
6 * Author: Vipin Sharma <vipinsh@google.com>
7 */
8 #ifndef _MISC_CGROUP_H_
9 #define _MISC_CGROUP_H_
10
11 /**
12 * enum misc_res_type - Types of misc cgroup entries supported by the host.
13 */
14 enum misc_res_type {
15 #ifdef CONFIG_KVM_AMD_SEV
16 /** @MISC_CG_RES_SEV: AMD SEV ASIDs resource */
17 MISC_CG_RES_SEV,
18 /** @MISC_CG_RES_SEV_ES: AMD SEV-ES ASIDs resource */
19 MISC_CG_RES_SEV_ES,
20 #endif
21 /** @MISC_CG_RES_TYPES: count of enum misc_res_type constants */
22 MISC_CG_RES_TYPES
23 };
24
25 struct misc_cg;
26
27 #ifdef CONFIG_CGROUP_MISC
28
29 #include <linux/cgroup.h>
30
31 /**
32 * struct misc_res: Per cgroup per misc type resource
33 * @max: Maximum limit on the resource.
34 * @watermark: Historical maximum usage of the resource.
35 * @usage: Current usage of the resource.
36 * @events: Number of times, the resource limit exceeded.
37 */
38 struct misc_res {
39 u64 max;
40 atomic64_t watermark;
41 atomic64_t usage;
42 atomic64_t events;
43 atomic64_t events_local;
44 };
45
46 /**
47 * struct misc_cg - Miscellaneous controller's cgroup structure.
48 * @css: cgroup subsys state object.
49 * @events_file: Handle for the misc resources events file.
50 * @res: Array of misc resources usage in the cgroup.
51 */
52 struct misc_cg {
53 struct cgroup_subsys_state css;
54
55 /* misc.events */
56 struct cgroup_file events_file;
57 /* misc.events.local */
58 struct cgroup_file events_local_file;
59
60 struct misc_res res[MISC_CG_RES_TYPES];
61 };
62
63 int misc_cg_set_capacity(enum misc_res_type type, u64 capacity);
64 int misc_cg_try_charge(enum misc_res_type type, struct misc_cg *cg, u64 amount);
65 void misc_cg_uncharge(enum misc_res_type type, struct misc_cg *cg, u64 amount);
66
67 /**
68 * css_misc() - Get misc cgroup from the css.
69 * @css: cgroup subsys state object.
70 *
71 * Context: Any context.
72 * Return:
73 * * %NULL - If @css is null.
74 * * struct misc_cg* - misc cgroup pointer of the passed css.
75 */
css_misc(struct cgroup_subsys_state * css)76 static inline struct misc_cg *css_misc(struct cgroup_subsys_state *css)
77 {
78 return css ? container_of(css, struct misc_cg, css) : NULL;
79 }
80
81 /*
82 * get_current_misc_cg() - Find and get the misc cgroup of the current task.
83 *
84 * Returned cgroup has its ref count increased by 1. Caller must call
85 * put_misc_cg() to return the reference.
86 *
87 * Return: Misc cgroup to which the current task belongs to.
88 */
get_current_misc_cg(void)89 static inline struct misc_cg *get_current_misc_cg(void)
90 {
91 return css_misc(task_get_css(current, misc_cgrp_id));
92 }
93
94 /*
95 * put_misc_cg() - Put the misc cgroup and reduce its ref count.
96 * @cg - cgroup to put.
97 */
put_misc_cg(struct misc_cg * cg)98 static inline void put_misc_cg(struct misc_cg *cg)
99 {
100 if (cg)
101 css_put(&cg->css);
102 }
103
104 #else /* !CONFIG_CGROUP_MISC */
105
misc_cg_set_capacity(enum misc_res_type type,u64 capacity)106 static inline int misc_cg_set_capacity(enum misc_res_type type, u64 capacity)
107 {
108 return 0;
109 }
110
misc_cg_try_charge(enum misc_res_type type,struct misc_cg * cg,u64 amount)111 static inline int misc_cg_try_charge(enum misc_res_type type,
112 struct misc_cg *cg,
113 u64 amount)
114 {
115 return 0;
116 }
117
misc_cg_uncharge(enum misc_res_type type,struct misc_cg * cg,u64 amount)118 static inline void misc_cg_uncharge(enum misc_res_type type,
119 struct misc_cg *cg,
120 u64 amount)
121 {
122 }
123
get_current_misc_cg(void)124 static inline struct misc_cg *get_current_misc_cg(void)
125 {
126 return NULL;
127 }
128
put_misc_cg(struct misc_cg * cg)129 static inline void put_misc_cg(struct misc_cg *cg)
130 {
131 }
132
133 #endif /* CONFIG_CGROUP_MISC */
134 #endif /* _MISC_CGROUP_H_ */
135